In general, in order to convey a heavy burden in a factory or the like, a conveyance cart that can move in a loaded state is employed.
In JP 2004-35239 A, there is disclosed a movable lift unit that can lift a product loaded on a liftable deck up to a predetermined height. In this lift unit, the liftable deck is lifted or lowered by driving a motor.
SUMMARY OF INVENTION
However, in some cases, the lift unit disclosed in JP 2004-35239 A may remain in a non-working state without being lifted even when the motor is driven in order to lift the liftable deck while a burden having a weight over a maximum payload is loaded. For this reason, the motor may suffer from an overload state, and reliability of the lift unit may be degraded.
It is therefore an object of this invention to improve reliability of the lift unit of the conveyance cart.
According to one aspect of this invention, a conveyance cart that can convey a loaded burden, includes: a body frame supported by a wheel; a deck provided liftably against the body frame to load a burden; an electric actuator electrically driven to expand or contract to lift or lower the deck; and a controller that is configured to supply an electric current to the electric actuator. The controller stops supply of an electric current to the electric actuator when a continuous driving time of the electric actuator is equal to or longer than a predetermined time.
The details as well as other features and advantages of this invention are set forth in the remainder of the specification and are shown in the accompanying drawings.